On such a feed table situated upstream of a cutting machine or a platen press, the sheet element is advanced against one or more front tabs by first means, such as endless belts or rollers, then is delivered by second means against one or more lateral positioning tabs before the front edge of the element is gripped by a series of grippers mounted on a gripper bar arranged on a chain system.
Such a device is used for precise lateral positioning of sheet elements which have already undergone one or more printing operations. Then a subsequent operation may be either a stamping process, for example hot foil stamping in a platen press, or a cutting and waste discharge operation in such a press. This subsequent operation must be performed in strict accordance with the preceding printing.
Lateral positioning devices are today used for jogging the sheets. They comprise firstly a lower roller driven in rotation and arranged transversely to the direction of movement of a sheet, close to a lateral tab situated on the left side of the table as viewed also in the direction of movement of the sheet, which is normally known as the operator's side. These devices then comprise an upper roller, vertically above the roller, mounted at the end of an arm which is in the top position at rest. This arm is lowered regularly on arrival of a sheet element against the frontal tabs, such that the upper roller grips the sheet element against the lower motorized roller which, by traction on the element, causes a correction movement as far as the lateral tab.